1. Field of the Invention
The present invention relates generally to a headphone for use with portable acoustic appliances or the like and, in particular but not exclusively, to a headphone having a cord reel for winding an input cord within a housing.
2. Description of the Related Art
Recently, headphones are increasingly utilized with the development of portable acoustic appliances. When a user carries a headphone with him or her, attention must be paid to an input cord.
Some of the conventional radios have an earphone and accommodate a cord reel for winding an input cord for the earphone therearound. The cord reel has a spring for biasing the input cord in the direction in which the input cord is wound in a housing, and also has an engaging means that engages with the input cord to bring it to a stop at any desired position during the winding thereof around the cord reel.
When the use of the earphone is desired, the input cord is drawn out by a desired length against the engaging means. On the contrary, when the input cord is stored within the housing, depressing a button for releasing the engaging means causes the input cord to be introduced into the housing by the force of the spring.
Such an arrangement cannot be employed in a housing of a headphone without any modification. The reason for this is that under the condition in which the user wears the headphone on his or her ears, if the engaging means is released in an attempt to introduce the input cord into the housing, there is a possibility that an input plug secured to a distal end of the input cord may impinge on his or her face or eye because of its momentum.
In order to prevent this, the inventors of this application have proposed a headphone having a safety mechanism in which the engagement by the engaging means cannot be released until the user first takes off the headphone from his or her head and then folds down a headband attached thereto. However, headphones of the ear-hanging type which are to be hung on the ears without using the headband are frequently used nowadays, and the aforementioned safety mechanism cannot be applied thereto.
The present invention has been developed to overcome the above-described disadvantages.
It is accordingly an objective of the present invention to provide an improved headphone having a cord reel that is capable of preventing an input plug secured to a distal end of the input cord from impinging on the user""s face or eye. The present invention is applicable to the headphones of the ear-hanging type.
In accomplishing the above and other objectives, the headphone according to the present invention includes a housing assembly having an electroacoustic transducer accommodated therein and an insertion hole defined therein, an input cord having an input plug secured to one end thereof, the input cord being connected at the other end thereof to the electroacoustic transducer, and a winding mechanism accommodated in the housing assembly for winding the input cord within the housing assembly. The winding mechanism includes a cord reel biased to wind the input cord therearound and an engagement member pivotally mounted in the housing assembly.
When the input plug is inserted into the insertion hole, the input plug rotates the engagement member in a first direction, which in turn allows the cord reel to wind the input cord therearound. On the other hand, when the input plug is removed from the insertion hole, the engagement member rotates in a second direction counter to the first direction, allowing the input cord to be drawn out of the housing assembly and preventing the cord reel from winding the input cord therearound.
This construction facilitates the winding of the input cord, and when the input plug is inserted into the insertion hole of the housing assembly in an attempt to wind the input cord around the cord reel, the input plug causes the engagement member to release the locking of the cord reel. As a result, the input cord is wound around the cord reel with the input plug retained in the insertion hole, making it possible to prevent the input plug from impinging on the user""s body.
Advantageously, the winding mechanism includes a spring member secured to the housing assembly for holding the input plug when the input plug is inserted into the insertion hole. This construction further enhances the safety of the headphone.
Conveniently, the engagement member has a locking piece and a lock releasing piece, both integrally formed therewith, and the cord reel has an outer periphery defining a plurality of notches or protrusions. The input plug is brought into contact with the lock releasing piece when the input plug is inserted into the insertion hole, while the locking piece engages with an edge of one of the plurality of notches or protrusions when the input plug is removed from the insertion hole.